The metal nuts and washers securing the grill on the outside unit of my heat pump rust over time. Not a big a deal. I just replace them.
However, I was wondering if I could use nylon washers and nuts instead. They wouldn't rust and they might help to dampen vibrations from the grill. Right now there is a metal flat washer, a lock washer, and a nut. I didn't see any nylon lock washers so I'd be using a nylon flat washer, a metal lock washer, and a nylon nut,
Here's a picture of the outdoor unit and the nylon washers and nuts.
In general, are nylon fasteners just as good (or better?) than metal for outdoor applications subject to weather?